I'm the opposite after returning from at trip there is usually some new food I had tried on my trip that I wish I could have again. My trip to the UK, I had THE BEST YORKSHIRE PUDDING EVER while in York and when at Disney I had Pooh's french toast at Crystal palace! YUM!!!
Mine is always something I was eating while there:
Vegas---crepes and Gouda cheese from Paris buffet, pizza from Hidden Pizza
Disney---Pecos Bill's nachos (something about their taco meat!) and anything from Les Halles
Louisiana---hurricanes, Cajun Mary's, Cajun chicken poboys, beignets
Mississippi---BBQ, fried chicken, any kind of cooked greens (turnip, collard, etc)
New Mexico---everything smothered in green chiles, blakes lotanurger
....that's how I feel about Italian food [outside the NYC area]....Mexican food because it's my favorite and I'm always disappointed in the Mexican food options outside of Southern California.
Bartolos' pizza!